MOMMIE DEAREST: Joan Crawford with kids Christina andChristopher, who were both written out of her will.Getty Images

After watching two episodes of ID’s newest series, “The Will: Family Secrets Revealed,” I’m convinced that it should have been called, “Against Their Will.”

The series persuaded me that no wealthy corpse will be left in peace as long as greedy, miserable heirs remain alive and kicking. And it only gets worse if the heirs have been adopted or turn out to be “illegitimate.”

The idea behind “The Will” is to dig up every dirty little secret behind the dirty business of who gets what after a rich, “Who’s Who” family member bites the dust.

Like which who’s who? How about the children of — yes! — Joan Crawford?

Tomorrow night’s premiere episode is as juicy as they come because Crawford, a big drunk, had four adopted children. The two oldest, Christina and Christopher, were totally written out of her will, while the youngest — twins named Cathy and Cindy — split $150,000 out of a $2-million estate. Joan gave the rest to charity, in a move that many believe was the final p.r. flourish of the image-obsessed star.

Why did Joan disinherit her first two children? “For reasons which are well known to them,” she stated in the will. Tomorrow, you will find out what those reasons may have been. (I don’t want to give it away.)

The episode goes into all the nasty business of how Christina and Christopher, a wounded Vietnam vet, fought for their tiny bit of the already mostly-eaten pie.

Next up? “The Estate of Hank Williams,” the country singer and songwriter, who died at 29. At the time, he was married with one child and another one on the way. But the second child, who was born five days after his death, wasn’t born to his wife.

If you think you’ve seen tenacity, wait until you see the story of Williams’ other child — who didn’t have a clue about the identity of her father or her mother until she was grown herself.

There’s nothing as certain as death and taxes, sure. But don’t forget the feuding heirs who fight over death and what’s left after taxes.